* [chore] Stricter ruff rules
* [chore] Furture lint rules and removal of flake8
* [ci] Bump github action versions
* [chore] Add additional test coverage
* Revert RNG switch to np.random.default_rng()
Restore use of the global np.random state in pseudo_Obs (misc.py) and the
prior id generation (fits.py), keeping seed behavior unchanged. The switch
to a module-local generator is out of scope for this lint-focused PR.
* Silence NPY002 on intentional legacy np.random calls
The RNG migration was reverted to keep np.random.seed() behavior, so add
per-line noqa: NPY002 on the three legacy np.random calls instead of the
Generator API.
* [Fix] Fix exception messages
